Terminal portions of plastic filament zippers



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D. O. TAYLOR TERMINAL PORTIONS OF PLASTIC FILAMENT ZIPPERS 196 Filed Nov.

3,333,305 TERMINAL PORTIONS OF PLASTIC FILAMENT ZIPPERS 1, 1965 D. O. TAYLOR Aug. l, 1967 2 Sheets-Sheet 2 Filed Nov.

United States Patent O 3,333,305 TERMINAL PORTIONS OF PLASTIC FILAMENT ZIPPERS Donald O. Taylor, Waterbury, Conn., assignor to Scovill Manufacturing Company, Waterbury, Coun., a corporation of Connecticut Filed Nov. 1, 1965, Ser. No. 505,925 3 Claims. (CI. 24-205.11)

The invention relates generally to zippers of the type employing continuous plastic filaments. Such filaments may be of the elongated coil type or the filament may take some meandering form which is not strictly a coil, Ibut which presents open loop portions extending from the edge lof a fabric Stringer on which the filament is mounted. For the sake of brevity, these zippers may be referred to simply as the coil filament type.

In preparing coil filament zipper stringers for end stops, the continuous filament must be cut at a point spaced from the tape end and a portion of the coil removed to provide a tape extension. The attachment of stop members on such tape extensions has always been a difficult problem in zippers of this type. The cut end of the coil must be secured so that it cannot back out or twist away from its proper place. Attempts to mold stop members or to clamp metal parts in place over the coil end have been only partially successful. This is due primarily to the fact that when pressure is applied, the coil and end tend to squirm away from the normal position.

This invention results in a finished product where the cut end of the coil is firmly anchored to the tape and sewing threads, and also to the cord when a cord is employed. The problem of producing this result is solved by a process involving the threading of the open loop portions near the end of the coil over a rigid pin which firmly holds the end portion of the coil while the stringer is supported with its tape bearing on a fiat die surface. Such a pin, particularly when a cord is present, wedges between the head portions of the loops and the cord to hold the entire end portion of the coil, and especially the extreme cut end so that the latter cannot squirm away when pressure is applied. While thus held, the end portion only of the coil may be fused, preferably by the use of an ultrasonic tool, bearing on the threads and cord, whereupon the fused material fiows not only into the tape and cord, but also into the stitching. This process has the further advantage of pulling the stitching tightly over the endmost complete loop portion so as further to strengthen the attachment of the coil to the tape.

Other objects and advantages of the invention will hereinafter more fully appear.

In the accompanying drawings, I have shown for purposes of illustration, one embodiment which the invention may assume in practice. In the drawings: j

FIG. 1 is a front View with parts in section, showing my invention applied to a separating end type zipper;

FIG. 2 is a top plan View showing the first step of the process of making my improved zipper;

FIG. 3 is a section on line 3--3 of FIG. 2;

FIG. 4 is a section on line 4-4 of FIG. 2 with the fusing step about to be initiated;

FIG. 5 is a longitudinal central section during the fusing step;

FIG. 6 is a perspective view of the supporting and threading tool used in my improved process;

FIG. 7 is a detailed view of the finished product;

FIG. 8 is a cross-section on line 8-8 of FIG. 7; and

FIG. 9 is a section similar to FIG. 5 with a portion of the cord and stitching removed and illustrating a modification.

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I have shown my invention as applied to a separating type zipper, and the advantages are especially important in such an assembly.

There are indicated two fabric tapes 9 and 10 to which are secured the fastening elements 11 and 12. These elements are of the continuous coil filament type in which the loops are somewhat flattened or elongated. A cord 13 extends through each coil leaving open spaces between the cord and the heads 14.

The fastening elements are secured in place, each by a line of stitching 15 which extends through the tape, through the cord and over the loop portions. A portion of each coil is removed over a substantial distance adjacent the tape end to produce a cut end portion 16 which lies against the tape and which extends to a point close to the tape edge. The stitching 15 extends. uninterruptedly over this cut end portion 16 through the cord and tape to the end of the tape. As seen in FIGS. 1 and 2, a portion of each of the tapes 9 and 10 is covered by a crosstape reinforcement 17.

The components of the separating bottom connection may be the usual ones employing a pin 18, which may abut or even overlap the cut end portion 16, an anchor tube 19 and the box end fitting 20. FIG. 1 also shows a slider 21 in position for insertion of the pin 18.

After the coils have been cut and the unwanted parts removed, they are ready for the first step in the process. Preferably, the operation is carried on with the two stringers of a complete zipper which are interengaged except near the end to which the pin 18 and tube 19 are to be applied. They are then placed against the fiat surface 22 of a die and pushed over a pair of pins 23 and 24 mounted on a block 25. These pins are properly dimensioned to enter the open loop portions: of the fastener elements and fit snugly between the cords 13 and the head portions 14 of the elements. As seen in FIG. 3, the pins may bear on the stitching threads 15 rather than directly against the cords. The block 25 has stop shoulders 26 and 27 so that the heads of the endmost complete loops of the coil may abut against them with the pins projecting into a plurality of open loops, preferably two or three on each side. The pins 23 and 24 thus firmly support the end portions of the coils while the coils are resting on the die surface 22 and while their heads 14 are bearing against a tongue 28 which projects from the block 25 centrally between the pins 23 and 24 for somewhat greater distances than the pins so as to maintain the entire end portions of the coils in a straight line.

The next or fusing step indicated in FIGS. 4 and 5 is preferably accomplished by an ultrasonic tool employing what is called a horn 29 having bifurcated portions 30 and 31 adapted to bear against the lines of stitching. While this horn may be dimensioned to cover a plurality of stitches as seen in FIG. 5, the pressure and thus the heat generated is concentrated in the region of the cut coil ends 16.

It will be understood that the plastic filament is of some material, such as nylon, which will soften under a degree of heat which will not affect the cotton material of the tape, cor-d or threads.

During the fusing action, the material of the filament will thus weld itself not only to the tape and cord, but also to the stitching which has been drawn down tightly over the endmost loop of each filament. During the process, it will be observed that the problem of preventing the cut end portions 16 from squirming out of place is solved by the novel method of threading them over the pins 23 and 24 while the stringers are rigidly supported from the bottom of the -die surface 22 and at their head ends by the tongue 28.

The result as seen on anenlarged scale in FIGS. 7 and 8 is a secure and reliable attachment of the end portions of the coils without the use of extra rein-forcing members and without interfering materially with the flexibility of the coils themselves. The stringers are thus ideally prepared by the attachment of end stop members such as those normally used in separating end connections.

In the modification shown in FIG. 9, the cord 13 is shown removed in the region of the pin 24. The stringers are shown in an inverted position so that the ultrasonic horn 29 bears on the tape side. Thus, when the horn is pushed against the tape, the cut end 16 of the coil and the associated portion of the cord will be pressed down against the flat surface 22.

What l claim is:

l. In a zipper fastener, a fabric tape, fastening means of the continuous plastic filament type carried by the tape and presenting a series of closely spaced and aligned open loop portions along the tape edge, said filament terminating a substantial distance from one end of the tape in an end portion which is positioned against the tape and which extends to a point close to said tape edge, and means for securing said filament to the tape comprising a line of stitching passing through the tape and over said loop portions, over said filament end portion and continuing through the tape beyond said end portion, said filament end portion being fused to said tape and stitching to anchor it firmly in place without materially affecting the flexibility of the adjacent loop portions.

2. In a zipper fastener as defined in claim 1, wherein said stitching is pulled tightly over the endmost complete loop portion into the fused filament end portion.

3. In a zipper fastener, a fabric tape, fastening means of the continuous plastic filament type carried by the tape and presenting a series of closely spaced and aligned open loop portions along the tape edge, said filament terminating a substantial distance from one end of the tape in an end portion which is positioned against the tape and which extends to a point close to said tape edge, a cord extending through said open loop portions, over said filament end portion, and therebeyond to the end of the tape, and means for secu-ring said filament to the tape comprising a line of stitching passing through the tape and cord throughout the length of the tape and over said open loop portions, said filament end portion being fused to said cord and tape whereby it is firmly anchored in place.

References Cited UNITED STATES PATENTS 2,532,456 1/1952 Poux 24--205.l6 3,103,728 9/1963 Wahl. 3,162,918 12/1964 Burbank.

BERNARD A. GELAK, Primary Examiner. 

1. IN A ZIPPER FASTERNER, A FABRIC TAPE, FASTENING MEANS OF THE CONTINUOUS PLASTIC FILAMENT TYPE CARRIED BY THE TAPE AND PRESENTING A SERIES OF CLOSELY SPACED AND ALIGNED OPEN LOOP PORTIONS ALONG THE TAPE EDGE, SAID FILAMENT TERMINATING A SUBSTANTIAL DISTANCE FROM ONE END OF THE TAPE IN AN END PORTION WHICH IS POSITIONED AGAINST THE TAPE AND WHICH EXTENDS TO A POINT CLOSE TO SAOD TAPE EDGE, AND MEANS FOR SECURING SAID FILAMENT TO THE TAPE COMPRIS- 